Art of converting high-boiling hydrocarbon oils



Nov. 18, 1930. E. E. BARTELS ART OF CONVERTING HIGH BOILING HYDROCARBON OILS Filed July 12, 1926 Patented Nov. 18,-

' UNITED s'umeis PATENT OFFICE- EDWARD E. BARTELS, OF WHITIN G, INDIANA, ASSIGNOR TO STANDARD OIL COMPANY, OF WHITING, INDIANA, A CORPORATION OF INDIANA ART OI CONVERTINGHIGH-BOILING HYDROCARBON OILS Application filed m 12,

The present invention relates to improve ments in processes and apparatus foreifecting the conversion of high boiling hydrocarbon oils into lower boiling hydrocarbon oils, such as gasoline, and will be fully understood from the following description, illustrated by the accompanying drawing, in which apparatus suitable for carrying the invention into effect is diagrammatically shown.

Referring more particularly to the drawings, the numeral 5 indicates a furnace setting in which is mounted a pipe coil 6, diagrammatically shown, which may be of any suitable type of construction. From the coil 6 a line 6 leads to the first of a plurality of enlarged chambers 7, which communicate by a liquid overflow line 8. Each of the chambers 7 may suitably be provided with a valved dis charge line 9. The upper portions of the env larged chambers 7 communicate through va-- por lines 10 with vapor manifold 11, which. leads ,to the lower portion of a suitable dephlegmator 12. From the upper portion of the dephlegmator 12 a vapor line 13 leads to the interior of an auxiliary condenser or reflux cooler 14. Vapors uncondensed in the latter pass out'through vapor lines 14 to a condenser 16, the condensed products passing out of the latter through line 17 to a receiver and. suitable means for maintaining pressure upon the system, the latter not being shown.

Products condensed in the dephlegmator 12 are discharged through the line 18, being picked up by the pump 19, preferably a surge pump or other pump suitable for handling hot liquids, and forced through the line 20 into the pipe 21 by which the oil to be treated is supplied to the coil 6.

Within the reflux condenser there is provided a coil 22 of any suitable construction, to which oil to be charged into the system is fed by any suitable ressure means through line 23. After passlng through the coil. 22, the oil leaves through the line 24 which. connects 1926. Serial No. 121,850,;

with the line 21 leading into the coil 6. Additional oil may be supplied to the line 21 through the valved connection 25, although such operation is not usually preferred in connection with this invention.

In carrying out the invention, the oil to be treated is supplied through the line 21' to the coil 6, in which it is brought to conversion temperature, say in excess of 700 F. A suitable temperature may be 7 75 to 825 F. The oil then passes through the line 6 into the first of the chambers 7, which are shown as lagged to retain the heat of theoil entering them. The oil overflows from the first of the chambers .7 into the second through the line 8. In the enlarged chambers 7 the temperature of the oil is maintainedat or only slightly below its temperature at the outlet from the coil 6, the oil being maintained in the enlarged chambers 7 for a sufficient period to permit a substantial conversion thereof into the desired low boiling product. If desired, the chambers 7 may be greatly heated to maintain conversion temperature therein. A greater or less degree of conversion may already have taken place in the coil 6 in which the oil was brought to conversion temperature, the conversion in the coil 6 being so limited, however, with respect to the velocity of the oil through the coil that substantially no coke deposition takes place therein. The

entire conversion of the high boiling oil taking place in the coil 6 and in the chambers 7 may be from to 40% or higher of low boiling products, based on the original oil treated, as determined by the character of the oil and the conditions of operation.

In the chambers 7 vaporization of the desired low boiling products together with some heavier boiling constituents takes place. The unvaporized oil may be removed through the valved discharge lines 9 continuously or intermittently as desired. In general it is preferred that the unvaporized oil be largely discharged from the second of the chambers, oc-

casional amounts being intermittently discharged from the first thereof.

The vapors leaving the chambers 7 enter the lower portion of the dephlegmator 12, within which there may be provided any suitable dephlegmating equipment (not shown), as bubble plates, screen plates, doughnut and disk baflie plates or the like. Some condensation of the vapors takes place Within the dephlegmator 12, the reflux condensate descending the column in countercurrent to the ascending vapors. The uncondensed vapors pass through the vapor line 13 into the auxiliary or reflux condenser 14, in which they come in contact with the coils 22 through which fresh stock feeding into the coil 6, is circulated. Vapors uncondensed in the reflux cooler ass out through the vapor line 15 to the con enser 16, where their condensable ortions are condensed. The condensate ormed in the reflux cooler 14 passes out through the trapped line 27, which is rovided with two valve-controlled branc cs 28 and 29. The pipe 28 leads into the vapor line 15 oing to the condenser 16 and the pipe 29 lea s from the lowest point in the trapped line 27 directly into the upper portion of the dephlegmator 12. 'The valves of the lines 28 and 29 are so controlled that the portion of the reflux returned to the dephlegmator 12 will produce the desired coohng action therein, the remaining portion of the condensate formed in the cooler 14 passing through the line 28 into the vapor line 15 and being mixed with the condensate from the vapors passing therethrough. It is to be understood, of course, that additional cooling means (not shown) may be applied in the dephlegmator 12 if desired.

In operating in accordance with the present invention, it is generally preferred that the entire supply of fresh oil being fed into the system to be treated pass through the line 23 and coil 22 in the reflux cooler 14, be ing preheated therein by the vapors issuing from the dephlegmator 12. The preheated feed stock is then supplied to the coil 6, in which itis brou ht to conversion temperature, together wit% the reflux condensate withdrawn from the dephlegmator 12 and charged into the coil by the pump 19 through the line 20. When operating in accordance with the present invention, it is not necessary to divide the stream of fresh oil going into the system, limiting the proportion of fresh oil passing in heat exchange with the vapors in the dephlegmating system b the requirements of the latter, as has on necessary in systems previously known. On the contrary, in carrying out the present invention, the entire feed stock or any desired proportion thereof may be passed through the coil 22 in heat exchange with the vapors from the enlarged chambers 7, and the operation of the dephlegmator 12 is independently controlled by controllin the proportion of condensate formed by eat exchange with the fresh stock which is returned in counter-current with the ascending vapors. In this way, the entire feed stock or any desired proportion thereof may be preheated by the vapors from the enlarged chamber wholly independently of the specific requirements of the dephlegmators for a cooling medium.

Any desired pressure from 4 to 5 atmospheres upward may be maintained upon the system, such pressure being preferably maintained through thecondenser. In general, a pressure of from 250 to 450 lbs. per square inch is referred, although higher or lower pressures may be used, as desired.

I claim:

1. The method of forming desired low boiling products of the nature of gasoline from higher boiling products which comprises passing the higher boiling oil to be converted through a confined passage in which it is heated under pressure to conversion tempera-- ture, the oil being passed through said passageway at a rate such as to prevent substantial deposition of coke therein, maintaining the oil at conversion temperature to effect the desired conversion thereof, separating the conversion products into a vapor portion including the vapors of the desired low boiling products and an unvaporized portion, pass ing the vapors through a dephlegmating chamber in countercurrent to reflux condensate, bringing the uncondensed vapors from said chamber into indirect heat conductive contact with fresh oil entering the system in a reflux condensing zone, separating the con- 2. The method of forming desired low boiling products of the nature of gasoline from higher boiling products which comprises passin the higher boiling oil to be converted throug a confined passage in which it is heated to conversion temperature under pressure, the oil being passed through said passageway at a rate such as to prevent substantial deposition of coke therein, maintaining the oil at conversion temperature toeifect the desired conversion thereof, separating the conversion products into a vapor portion and an unvaporized portion, passin the vapors through a dephlegmatin cham er in countercurrent to reflux condensate, passing all of the fresh oil entering the system into indirect heat conductive contact with the uncondensed vapors from said dephlegmating chamber in a reflux condensing zone separat-.

uncondensed vapors into a condenser and charging the feed stock preheated by said vapors into the confined passafiewa EDWARD E. AR LS 

